ML082890872
| ML082890872 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 10/01/2008 |
| From: | Division of Operating Reactor Licensing |
| To: | |
| Wengert, Thomas NRR/DORL 415-4037 | |
| References | |
| TAC MD9465 | |
| Download: ML082890872 (21) | |
Text
Prairie Island 2R25 Outage*
NRC Phone Call and NRC Discussion Points**
October 1, 2008
- The attached information has not been validated. In many cases, it is preliminary information from ongoing activities. To our knowledge, it is the best information available as of 10 AM on the date prior to this report and may be changed following further review and analysis.
- 2R25 NRC Discussion Points used as template for this presentation.
Participants
~ Prairie Island (NSP MN)
~ Kari Den Herder (SG Engineer)
~ Richard Deopere (ET Specialist)
~ Mike Heller (SG Project Supervisor)
~ Jeff Kivi (Licensing)
~ Robert Murray (Inspection & Materials Supervisor)
~ Scott Redner (ET Level III QDA)
~ Steve Skoyen (Engineering Programs Manager)
~ Ben Stephens (SG Program Engineer)
~ Areva, Lynchburg
~ Jim Begley (CMOA analyst)
Current Status of 2R25 SG Inspection (As of 1000 on September 30,2008)
Category 21 SG 22SG ET Acquisition 92.3 85.5
(% completed)
ET Analysis 89.9 74.4
(% completed)
- of Pluggable 16 4 Tubes
- of Re-Roll 190 115 Candidates
Q1: Discuss any trends in the amount of primary-to secondary leakage observed during the recently completed cycle.
~ 21 Steam Generator maximum steady state leakage by tritium was less than detectable to <
1 gallon per day over the last cycle
~ 22 Steam Generator maximum steady state leakage by tritium was less than detectable to
<1.1 gallons per day over the last cycle PI 2R25 SG NRC Phone Call 4
Q2: Discuss whether any secondary side pressure tests were performed during the outage and the associated results.
~ Due to very low primary to secondary leakage, no pressure tests were done to look for tube leakage PI 2R25 SG NRC Phone Call 5
Q3: Discuss any exceptions taken to the industry guidelines.
~ No exceptions were or will be taken from industry guidelines.
Q4: For each SG, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion transition, U-bends with a rotating probe), the scope of the inspection (e.g., 100 percent of the dents/dings greater than 5 volts and a 20% sample between 2 and 5 volts), and the expansion criteria.
~ Prairie island 2R25 steam generator inspection plan is attached on the following sheet.
Inspection Plan SCOPE PROBE TYPE S/G 21 S/G 22 Full Length 0 Bobbin 100% 100%
Rows 1 through 4 U-Bends MRPC 100% 100%
Rows 5 through 8 U-Bends f} MRPC 33% 33%
Hot Leg Tubesheet MRPC 100% 100%
1690 Hot Leg Roll Plugs C) MRPC 25% 25%
Supplemental e MRPC 100% 100%
Post In Situ Pressure Test MRPC 100% 100%
Plug Visual N/A 100% 100%
Baseline New Re-Rolls MRPC 100% 100%
o Except the bend portion of row I through 4 u-bends.
8 Expansion plan defined in plant procedure 2H25.1.
c) Plug samples are considered proactive informational sample plans that are not subject to the periodicity requirements ofT.S.5.5.8.d.3.
o ADR, CUD, DEP, DNI, TSP DNT ;:::: 2.0V, Freespan DNT ;:::: 5.0V, DRI, DSI, DTI, TSP INR;:::: 1.5V, MBM, MRI, NQI, PLP (Bound MRPC PLP's), PSI, Cold Leg Thinning;:::: 40% or < 40% and;:::: 1.5V.
Q5: For each area examined (e.g., tube supports, dents/dings, sleeves, etc), provide:
A summary of the number of indications identified to-date of each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition).
For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle.
In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).
Analysis Status Analysis Status (percent completed) SG 21 SG 22 as of 1000 on September 30, 2008:
Hot Cold Hot Cold Bobbin 99.7 92.5 0 84.1 U-Bend MRPC 4.7 N/A 33.7 N/A Tubesheet Crevice MRPC 99.9 N/A 86.8 N/A Hot Leg Roll Plug MRPC 100 N/A 100 N/A Supplemental MRPC 87.8 0 0 0 Post In Situ MRPC 0 0 0 0 Plug Visual 100 80 98 97 Baseline New Re-Rolls 0 0 0 0 PI 2R25 SG NRC Phone Call 10
SG 21 Analysis Results to Date Degradation Mode and Location (Indications) # Volt Depth Length New Excludes all indications below the F* and EF* Distance Mech.
Volumetric Wear at New Anti-Vibration Bars (AVB)~ ~ 1") 21 1.70 32 N/A N VOlumetric Wear at Old AVB's (free span)(> 1") 52 3,36 45 N/A N Volumetric Wear at PLP's (1998 In Situ Neighbors) 2 0.55 31 N/A N Volumetric Thinning at Cold Leg Tube Support Plates 70 3.69 44 N/A N VOlumetric Thinning at Cold Leg Top of Tubesheet a N/A N/A N/A N Volumetric Thinning at Hot Leg Tube Support Plates a N/A N/A N/A N Volumetric Thinning at Hot Leg Top of Tubesheet a N/A N/A N/A N Axial ODSCC at Hot Leg Sludge Pile a N/A N/A N/A N Axial ODSCC at Hot Leg Crevice 11 0.24 N/A 1.19 N Axial ODSCC at Hot Leg Tube Support Plates a N/A N/A N/A N Axial PWSCC at Hot Leg Roll ExpansionslTube Ends 194 1.43 N/A 0.34 N Circ. PWSCC at Hot Leg Roll ExpansionslTube Ends a N/A N/A N/A N Circ. ODSCC at a Re-Roll Expansion a N/A N/A N/A N Axial PWSCC at U-bends a N/A N/A N/A N Circ. PWSCC at U-bends a N/A N/A N/A N ODSCC/PWSCC at Dents a N/A N/A N/A N ODSCC/PWSCC at Plugs a N/A N/A N/A N Structural and accident induced leakage integrity was maintained during the previous cycle PI 2R25 SG NRC Phone Call 11
SG 22 Analysis Results to Date Degradation Mode and Location (Indications) # Volt Depth Length New Excludes all indications below the F* and EF* Distance Mech.
VOlumetric Wear at New Anti-Vibration Bars (AVB)t: 2: 1") 38 2.67 38 N/A N Volumetric Wear at Old AVB's (free span)(> 1") 32 2.73 42 N/A N Volumetric Wear at PLP's 0 N/A N/A N/A N VOlumetric Thinning at Cold Leg Tube Support Plates 115 4.79 52 N/A N Volumetric Thinning at Cold Leg Top of Tubesheet 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Tube Support Plates 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Top of Tubesheet 0 N/A N/A N/A N Axial ODSCC at Hot Leg Sludge Pile 0 N/A N/A N/A N Axial ODSCC at Hot Leg Crevice 3 0.15 N/A 0.37 N Axial ODSCC at Hot Leg Tube Support Plates 0 N/A N/A N/A N Axial PWSCC at Hot Leg Roll Expansions/Tube Ends 115 1.25 N/A 0.36 N Circ. PWSCC at Hot Leg Roll ExpansionslTube Ends 0 N/A N/A N/A N Circ. ODSCC at a Re-Roll Expansion 0 N/A N/A N/A N Axial PWSCC at U-bends 0 N/A N/A N/A N Circ. PWSCC at U-bends 0 N/A N/A N/A N ODSCC/PWSCC at Dents 0 N/A N/A N/A N ODSCC/PWSCC at Plugs 0 N/A N/A N/A N Structural and accident induced leakage integrity was maintained during the previous cycle PI 2R25 SG NRC Phone Call 12
Q6: Describe repair/plugging plans.
Pre Outage Predicted Repairs SCOPE S/G 21 S/G 22 In Situ Pressure Test 5 5 AR1 - 6" Re-Roll 411 168 AR2 - 8" Re-Roll 198 66 ARE - Elevated Re-Roll 13 11 Hot Leg Roll Plugs 29 13 Cold Leg Roll Plugs 29 13 PI 2R25 SG NRC Phone Call 13
Planned Repairs (Based on 930/0 inspected)
SCOPE S/G 21 S/G 22 In Situ Pressure Test 0 0 AR1 - 6" Re-Roll 101 95 AR2 - 8" Re-Roll 71 17 ARE - Elevated Re-Roll 18 3 Hot Leg Roll Plugs 16 4 Cold Leg Roll Plugs 16 4 PI 2R25 SG NRC Phone Call 14
Q7: Describe in-situ pressure test and tube pull plans and results (as applicable and if available).
~ We have no plans to pull tubes for unit 2, as part of a licensed repair program.
~ Status - No tube pull needed.
~ We are planning on performing up to 10 in situ tests based on inspection results.
~ Status - No in situ needed.
Q8: Discuss the following regarding loose parts:
- 1) what inspections are performed to detect loose parts
- 2) a description of any loose parts detected and their location within the SG
- 3) if the loose parts were removed from the SG
- 4) indications of tube damage associated with the loose parts
- 1. A) All bobbin data is evaluated for possible loose parts (PLP) and PLP wear using manual analysis by primary.
B) Secondary uses Computer Data Screening (CDS) with a PLP specific sort from TSH + 0.3" to 07H + 2.00" and from TSC + 0.3" to 07C + 2.00" and various wear detection sorts from TSH - 1.0" to TSC 1.0".
C) Resolution tertiary review is conducted on all bobbin coil periphery tubes, two tubes deep for PLP's.
D) All MRPC data is evaluated for PLP's.
E) All bobbin PLP indications are tested with MRPC.
F) All MRPC PLP indications are bounded radially by one tube at the same elevation.
G) Any PLP that cannot be resolved with ECT are inspected from the secondary side for resolution.
H) Top of Tubesheet Remote Visual Inspection: Peripheral & In-bundle.
- 2. New MRPC PLP Indications:
SO HL Top ofTSH CL Top ofTSH 21 1 0 22 9 0
- 3. A). SG 21 secondary side FOSAR follows sludge lancing this week B). SG 22 secondary side FOSAR will be done this week
- 4. There is no wear associated with any of the PLP indications.
- 5. Based on FOSAR experience and historical lookups, the PLP indications are most likely sludge rocks. Visual confirmation will be conducted with the FOSAR inspection.
Q9: Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feedring inspections, sludge lancing, assessing deposit loading, etc.).
~ FOSAR results previously discussed.
~ SP 2534 Stealll Generator Internals Inspection for 21 SG
~ SG Steam Drum Inspection planned this week:
~Tube Bundle Wrapper
~ Feedwater Ring/Thermal Sleeve
~ Moisture Separation Equipment
~ Top of Tubesheet Region planned after sludge lancing PI 2R25 SG NRC Phone Call 19
QI0: Discuss any unexpected or unusual results.
~No unexpected or unusual conditions detected during 2R25.
Q11: Provide the schedule for SG-related activities during the remainder of the current outage.
~ ET examinations are scheduled to be completed later this week.
~ In-situ testing is not required at this time.
~ Repairs are Projected to be completed by October 6.
~ Manway installation is scheduled to be completed on October 12 or earlier.